/******************************************************
The simple hash table utility

(c) 1997 Innobase Oy

Created 5/20/1997 Heikki Tuuri
*******************************************************/

#include "hash0hash.h"
#ifdef UNIV_NONINL
#include "hash0hash.ic"
#endif

#include "mem0mem.h"

/****************************************************************
Reserves the mutex for a fold value in a hash table. */

void hash_mutex_enter(
    /*=============*/
    hash_table_t *table, /* in: hash table */
    ulint fold)          /* in: fold */
{
  mutex_enter(hash_get_mutex(table, fold));
}

/****************************************************************
Releases the mutex for a fold value in a hash table. */

void hash_mutex_exit(
    /*============*/
    hash_table_t *table, /* in: hash table */
    ulint fold)          /* in: fold */
{
  mutex_exit(hash_get_mutex(table, fold));
}

/****************************************************************
Reserves all the mutexes of a hash table, in an ascending order. */

void hash_mutex_enter_all(
    /*=================*/
    hash_table_t *table) /* in: hash table */
{
  ulint i;

  for (i = 0; i < table->n_mutexes; i++)
  {
    mutex_enter(table->mutexes + i);
  }
}

/****************************************************************
Releases all the mutexes of a hash table. */

void hash_mutex_exit_all(
    /*================*/
    hash_table_t *table) /* in: hash table */
{
  ulint i;

  for (i = 0; i < table->n_mutexes; i++)
  {
    mutex_exit(table->mutexes + i);
  }
}

/*****************************************************************
Creates a hash table with >= n array cells. The actual number of cells is
chosen to be a prime number slightly bigger than n. */

hash_table_t *hash_create(
    /*========*/
    /* out, own: created table */
    ulint n) /* in: number of array cells */
{
  hash_cell_t *array;
  ulint prime;
  hash_table_t *table;
  ulint i;
  hash_cell_t *cell;

  prime = ut_find_prime(n);

  table = mem_alloc(sizeof(hash_table_t));

  array = ut_malloc(sizeof(hash_cell_t) * prime);

  table->adaptive = FALSE;
  table->array = array;
  table->n_cells = prime;
  table->n_mutexes = 0;
  table->mutexes = NULL;
  table->heaps = NULL;
  table->heap = NULL;
  table->magic_n = HASH_TABLE_MAGIC_N;

  /* Initialize the cell array */

  for (i = 0; i < prime; i++)
  {
    cell = hash_get_nth_cell(table, i);
    cell->node = NULL;
  }

  return (table);
}

/*****************************************************************
Frees a hash table. */

void hash_table_free(
    /*============*/
    hash_table_t *table) /* in, own: hash table */
{
  ut_a(table->mutexes == NULL);

  ut_free(table->array);
  mem_free(table);
}

/*****************************************************************
Creates a mutex array to protect a hash table. */

void hash_create_mutexes(
    /*================*/
    hash_table_t *table, /* in: hash table */
    ulint n_mutexes,     /* in: number of mutexes, must be a
                         power of 2 */
    ulint sync_level)    /* in: latching order level of the
                         mutexes: used in the debug version */
{
  ulint i;

  ut_a(n_mutexes == ut_2_power_up(n_mutexes));

  table->mutexes = mem_alloc(n_mutexes * sizeof(mutex_t));

  for (i = 0; i < n_mutexes; i++)
  {
    mutex_create(table->mutexes + i);

    mutex_set_level(table->mutexes + i, sync_level);
  }

  table->n_mutexes = n_mutexes;
}
